My experience a couple years ago when I made Premier for the first time and then last year when I made 1P is that the benefits are available as soon as the miles post to your account, but that there will likely be some lag in things happening automatically. As an example, I often had to call United to get E+ seating after booking my flights, as they weren't shown as available when I booked. Eventually, things started happening automatically.

You'll be a 2P through February 09. It's good for the year in which you make the level and the next year + 2 months.